[ghc-steering-committee] Proposal #638: Prefix form for MkSolo# (Recommend Accept)

[Adam Gundry]

I also agree that we should accept. We need some name for the unit 
unboxed tuple data constructor, and MkSolo# seems to fit with what we 
currently have.

Simon's suggestion that we rethink the naming of the tuple type 
constructors seems to be a separate question. I think it warrants a new 
proposal/amendment if anyone feels strongly enough, rather than blocking 
this proposal, especially given that the original proposal's type names 
are already implemented.

Adam


On 14/03/2024 10:33, Matthías Páll Gissurarson wrote:
> I agree with the sentiment here, having Type0 and Type1 as the canonical 
> names would have been preferable in the original proposal.
> However, this amendment doesn't touch on that: it only changes the 
> constructor.
> 
> We'd still want MkSolo# even if Solo was the synonym, due to the 
> ambiguity described in the amendment.
> Renaming the canonical types would be a further, separate amendment to 
> the original proposal.
> 
> I believe we should accept the amendment, and consider a 
> separate amendment later.
> 
> On Tue, 12 Mar 2024 at 09:49, Simon Peyton Jones 
> <simon.peytonjones at gmail.com <mailto:simon.peytonjones at gmail.com>> wrote:
> 
>         Unless I'm misreading, the proposal is only about the
>         constructors' name. Which you don't propose to change, do you?
> 
> 
>     Yes. I was questioning the proposal itself rather than the amendment.
> 
>     S
> 
>     On Tue, 12 Mar 2024 at 09:43, Arnaud Spiwack
>     <arnaud.spiwack at tweag.io <mailto:arnaud.spiwack at tweag.io>> wrote:
> 
>         Unless I'm misreading, the proposal is only about the
>         constructors' name. Which you don't propose to change, do you?
> 
>         (that being said, I think I agree with your comment that the
>         name of the type ought to have been `Tuple1`, it'd make more sense)
> 
>         On Tue, 12 Mar 2024 at 10:38, Simon Peyton Jones
>         <simon.peytonjones at gmail.com
>         <mailto:simon.peytonjones at gmail.com>> wrote:
> 
>             Well this proposal deepens the commitment to an exception
>             for Solo and Solo#.   But I'm not really objecting, just asking.
> 
>             Simon
> 
>             On Tue, 12 Mar 2024 at 09:34, Arnaud Spiwack
>             <arnaud.spiwack at tweag.io <mailto:arnaud.spiwack at tweag.io>>
>             wrote:
> 
>                 In favour.
> 
>                 Simon: I don't think your objection pertains to this
>                 particular proposal amendment, does it? Rather it's a
>                 further change to the original proposal that you'd like
>                 to see.
> 
>                 On Mon, 11 Mar 2024 at 11:48, Simon Peyton Jones
>                 <simon.peytonjones at gmail.com
>                 <mailto:simon.peytonjones at gmail.com>> wrote:
> 
>                     Thanks Matthias
> 
>                     I'm generally supportive, but please see my comment
>                     exploring a minor alternative
>                     <https://github.com/ghc-proposals/ghc-proposals/pull/638#issuecomment-1988147639>.
> 
>                     Simon
> 
>                     On Sat, 9 Mar 2024 at 00:12, Matthías Páll
>                     Gissurarson <mpg at mpg.is <mailto:mpg at mpg.is>> wrote:
> 
>                         Greetings committee!
> 
>                         In
>                         [proposal #638](https://github.com/ghc-proposals/ghc-proposals/pull/638 <https://github.com/ghc-proposals/ghc-proposals/pull/638>),
>                         @int-index proposes that we introduce a prefix
>                         form of MkSolo#, and apparent oversight in
>                         proposal #475 [Non-punning list and tuple
>                         syntax](https://github.com/ghc-proposals/ghc-proposals/pull/475 <https://github.com/ghc-proposals/ghc-proposals/pull/475>).
> 
>                         Previously, you would write `(# a #)` to
>                         construct a `Solo# a`.
>                         But the question is: what would be the prefix
>                         form of this constructor?
>                         It can't be `(# #)`, because this is already
>                         defined as a constructor of `Unit#`!
> 
>                         This amendment proposes the `MkSolo#`
>                         constructor, having us write `MkSolo# a` for the
>                         prefix form. The discussion seems unanimous,
>                         after care was taken to clarify that a fully
>                         applied `MkSolo# a` would still be pretty
>                         printed as `(# a #)`, avoiding programmer confusion.
> 
>                         It seems quite straightforward to me, so:
> 
>                         I recommend accepting this amendment to #475.
> 
> 
>                         -- 
>                         -- Matthías Páll Gissurarson <http://mpg.is/>


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Adam Gundry, Haskell Consultant
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